The proposed study will conduct a small randomized trial to test the effectiveness of the collaborate care model (CCM) for homeless women with alcohol use disorders (AUD) and risky drinking in a large Health Care for the Homeless (HCH) primary care setting. It is well documented that the CCM yields numerous benefits for primary care patients with chronic conditions, ranging from depression to asthma and diabetes. Researchers and clinicians have argued that the CCM holds promise for individuals with significant AUD and co-occurring problems. As yet however, this approach has not been adequately applied and studied for homeless populations. Our goal is to adapt and determine the effectiveness of the CCM on improving AUD and risky drinking among homeless women. In keeping with recent developments in the substance abuse treatment literature, we will also assess changes in a wide range of outcome measures, including: alcohol use and related problems, mental health problems, functional status, housing status, and service utilization. We will also examine the effectiveness of the CCM on homeless women's initiation, engagement, and retention in appropriate AUD treatment as compared to usual care. This study will contribute knowledge about the fit between the CCM model and AUD and risky drinking treatment in primary care, and will provide substantive findings that point clinicians and policymakers towards better ways to address the complex needs of a highly at-risk population. The CCM model is ideally suited to the complex, co-occurring problems of homeless women, who comprise one of the fastest growing segments of the homeless population. Alcohol use disorders alone or combined with other drug use disorders has been reported in 60% of homeless women. Homeless women's substance abuse commonly co-occurs with other problems including depression, posttraumatic stress disorder, poor physical health, victimization, high risk sexual practices, and difficulty exiting homelessness. The CCM is one of the few evidence-based approaches that offers a strategy for coordinating care for patients with multiple co-morbidities with documented effectiveness. The specific aims of the study are as follows: 1) To finalize an adaptation of the CCM for homeless women with AUD and risky drinking, including a) preparation of a treatment protocol (manual, training, and tracking) and b) assessment of intervention feasibility, acceptability, and fidelity;2) To conduct a small randomized trial to determine the effectiveness of the CCM for homeless women with AUD and risky drinking on increasing initiation, engagement, and retention in AUD treatment;and, 3) To establish preliminary outcomes and effect sizes for the effectiveness of the CCM on AUD and risky drinking, alcohol use consequences, mental and physical functioning and housing outcomes among homeless women to inform a larger scale RCT. PUBLIC HEALTH RELEVANCE: It is well documented that the collaborative care model (CCM) yields numerous benefits for primary care patients with chronic conditions. As yet however, this approach has not been adequately applied and studied for homeless populations. Our goal is to adapt and determine the effectiveness of the CCM on improving AUD and risky drinking among homeless women in a large Health Care for the Homeless (HCH) primary care setting. This study will contribute knowledge about the fit between the CCM model and treatment for AUD and risky drinking in primary care, and will provide substantive findings that point clinicians and policymakers towards better ways to address the complex needs of a highly at-risk population.